This invention relates to dynamoelectric machines with internal frame walls and to the method of fabricating the machine with such internal frame walls.
Electric motor, and particularly fractional horsepower motors are widely used or applied to various applications requiring various speed and other related controls. Further, a basic motor construction incorporates an annular stator unit mounted within a round frame. The opposite ends of the round frame are closed by bearing frames or bearing plates, each of which include a rotor core aligned with the stator core and rotatably mounted by a shaft extending from the opposite ends of the rotor core and journaled in the bearings in the bearing frames. The frame may be formed of an extended length to define a space adjacent one end of the motor within which a lead circuit board unit is provided for interconnecting of the windings to the incoming power supply. In many applications, a centrifugal starting switch unit is also mounted with the space for controlled starting of the motor with an automatic disconnect of a start winding. Electronic control systems have also been widely developed for controlling the operation of the motor, either through manual or sensed conditions. Electronic controls present particular problems and considerations from the standpoint of isolating the control components from adverse environments. Thus, moisture, dirt and the like can adversely affect electronic controls. Consequently, the controls are generally housed in a separate protective enclosure secured to the motor structure or in spaced relation thereto and interconnected to a suitable connecting cable.
The motors to which the present invention has been applied are widely used in ventilating and exhaust fan applications, water and other fluid pumping systems and the like. Generally, the motor is formed with a shaft extension on one end for coupling to the load such as a fan, pump or the like. The opposite end of the motor is generally closed with the shaft terminated within an end bearing member. The U.S. patent application of King, entitled "Electric Motors Having Integral Control Housing And Method Of Fabrication", filed Feb. 6, 1989 with Ser. No. 07/306,887 and assiged to a common assignee with the present application, discloses a separate end cap secured to an end bearing frame of a motor to define a separate control chamber particularly adapted for customizing a standard motor module to various applications and specifications including modern electronic control circuitry, and particularly adapted to the several applications noted above. A multiple compartmented structure is disclosed in the co-pending application/of King et al entitled "Multiple Compartmented Dynamoelectric Machine", filed on Oct. 26, 1989 with Ser. No. 427,441 and assigned to a common assignee herewith. As more fully disclosed in the above application, a single integrated cylindrical or round motor frame has the stator core secured within an intermediate location. At least three compartment walls are secured in axially spaced relation in a round frame. Two of the wall members are constructed as end bearing frames and are secured within the round motor frame to rotatably support the rotor shaft and thereby the rotor unit within the stator bore. The third wall is located and secured within the round motor frame and in combination with one of the bearing frames defines a control or auxiliary component compartment, as more fully disclosed therein. Additional wall structures can be incorporated into the cylindrical frame to form additional auxiliary component chambers or compartments which are essentially closed, except for such openings required for the particular auxiliary component within the compartment. Finally, the multiple compartment walls within the frame are preferably similar wall structures and connected by similar wall attachment to the cylindrical frame to provide for effective and cost efficient assembly. The present invention is particularly directed to an effective structure and attachment method for mass production of integral fractional horsepower motors or the like where cost is of practical signifiance.